Collars for lens loops

ABSTRACT

Collars are disposed on loops of intraocular lenses for improved fixation of loops in rims of capsular bags of eyes. A collar may preferably be positioned on an outer portion of a loop and retained on the loop by an enlarged end portion of the loop.

BACKGROUND AND SUMMARY OF THE INVENTION

In the implanting of intraocular lenses in human eyes, particularly where accommodation is to be provided, it is important that loops of lenses be fixated within the rim of the capsular bag of the eye to maintain correct, accurate movement of the optic under the action of the ciliary muscle.

As is known in the art, loops, haptics, etc., disposed in the capsular bag rim, are intended to become fixated by fibrosis developed therein following surgical removal of a portion of the anterior capsular bag.

It is possible, although rare, that loops and certain other lens features engaged in the rim of the capsular bag may lose some degree of fixation or undergo some disengagement from the capsular bag rim. Lenses in which such problem might possibly arise include the well-known type of lens wherein arcuate loops extend oppositely from an optic; the lenses of Applicant's pending application, Ser. No. 08/858,978 entitled “Accommodating Intraocular Lens Having T-shaped Haptics”; and Applicant's pending application Ser. No. 08/947,113 entitled “Intraocular Lenses With Fixated Haptics”.

The present invention provides collar components for positioning on loops of lenses in the rim of the capsular bag of the eye, thus to enhance engagement of the loop and collar in the bag rim.

In a typical or preferred utilization of the collar on the invention, the collars are disposed on a lens comprising an optic having two haptics extending therefrom, at least one loop extending from each haptic, with the loops having enlarged end portions, whereby tubular collars disposed on the loops are retained thereon by enlarged end portions.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is an elevational view of a lens having haptics with loops extending oppositely and with collars of the invention thereon;

FIG. 2 is a fragmentary perspective view of a loop with collar thereon and disposed in the rim;

FIG. 3 is a fragmentary perspective view which shows a collar having a slit therein and disposed on a loop;

FIG. 4 is a perspective view of a collar with features thereon for enhanced engagement in the rim portion of a capsular bag;

FIG. 5 is a perspective view of a collar of the invention having a frusto-conical lumen therein;

FIG. 6 is an enlarged sectional view of a lens with oppositely disposed arcuate loops extending from an optic into engagement with the rim portion of a capsular bag and having collars thereon;

FIG. 7 shows collars of the invention disposed on loops extending from haptics of a lens; and

FIG. 8 is an elevated view showing collars of the invention on loops extending from the outer edge of an annular haptic.

DESCRIPTION OF THE PREFERRED EMBODIMENTS

Referring to FIG. 1 of the drawings, a preferred form of intraocular lens 10 with which the collars of the invention may be utilized, has flexible haptics 14 extending laterally oppositely from an optic 12. The haptics are plate haptics having arcuate outer edges. The loops, when unrestrained, are somewhat less curved in configuration than shown. The lens, including the optic, haptics, and loops are preferably formed of resilient, semi-rigid material, such as silicone, acrylic or hydrogel.

As is well known in the art, an intraocular lens, such as that of FIG. 1, is implanted in the capsular bag of an eye after removal of the natural lens. The lens is inserted into the capsular bag via a generally circular opening cut in the anterior capsular bag of the human lens, and through a small opening in the cornea or sclera.

With the outer ends of the haptics positioned in the cul-de-sac of the bag, as shown, the loops 16 are resiliently urged in close proximity with the bag cul-de-sac, the loops being deflected in the configuration shown.

Knobs 22 are defined on the outer end portions of the loops for improved securement in the capsular rim or cul-de-sac by engagement with fibrosis which develops in the capsular bag following the surgical removal of the central portion of the anterior capsular bag.

A collar 24 of the invention is disposed on each loop 16 in positions shown when the lens is positioned in the eye. The collars are preferably fabricated of a relatively hard material, such as polyimide, PMMA, or nylon, whereas the loops are typically formed of a flexible material, such as silicone, acrylic or hydrogel, as earlier mentioned.

Collars may be installed and disposed on loops by different procedures. A collar may be provided with a longitudinal slit (FIG. 3) to enable it to be deformed or spread open during positioning about a collar. Another procedure disposing a collar on a loop is to dispose a loop in an appropriate recess in a mold, then molding the loop to extend within and through the collar. Another procedure is to fabricate the loop of a hydrogel or acrylic material, slide the collar on the loop, then hydrolyze the loop, thus expanding the loop and the knob thereon, whereby the unexpanded loop is retained by the enlarged knob at the end of the loop.

Referring to FIGS. 4 and 5, a collar of the invention may incorporate various features for enhancement of fixation in the capsular bag. Such features may include knurling indicated at 26, annular ridges or rings 28 and a frusto-conical lumen or passage 30 in a collar.

A collar on a loop does not interfere with the stretchability of a loop, loop elasticity enables a loop to flex and stretch while the collar is engaged thereabout and in the rim of a capsular bag for fixing the lens in the capsular bag. The collar is positioned on an outer portion of a loop in proximity to a knob at the end of the loop in the procedure of inserting the lens into the eye, and remains so positioned after fibrosis is complete. The knob retains the collar on the loop to prevent the loop from slipping from the collar. As stated, the collar provides improved fixation in the peripheral rim or cul-de-sac of the capsular bag. To aid in retaining the collar adjacent the knob on the end of the loop, a small protrusion 32 may be defined on a loop, as shown in FIG. 7, the protrusion being sized to allow a collar to be slipped thereover after the loop is formed in the manufacture of the lens.

FIGS. 6 to 8 show certain of the various forms of lenses with which the collars of the invention may be utilized. FIG. 6 illustrates a type of lens well known in the art, wherein loops extend arcuately from an optic and into engagement with the capsular rim of an eye, with collars of the invention adjacent to knobs at the ends of the loops. FIG. 7 shows a lens having plate haptics and arcuate loops, with protrusions 32, extending from respective edge portions of the haptics transversely across the haptics, with collars thereon retained by knobs. FIG. 8 shows a lens having an annular plate haptic disposed about an optic, and a plurality of loops extending arcuately therefrom with collars of the invention retained by knobs on the ends of the loops.

Thus there have been shown and described collars for lens loops which fulfill all the objects and advantages sought therefor. Many changes, modifications, variations and other uses and applications of the subject invention will, however, become apparent to those skilled in the art after considering this specification together with the accompanying drawings and claims. All such changes, modifications, variations and other uses and applications which do not depart from the spirit and scope of the invention are deemed to be covered by the invention which is limited only by the claims which follow. 

The inventor claims:
 1. An intraocular lens comprising: an optic, at least two flexible fixation loops connected with the optic and extending into engagement in a peripheral rim of a capsular bag of eye, at least one of said loops having an enlarged outer end portion, and a substantially tubular collar disposed about said at least one loop for engagement thereof in said capsular bag peripheral rim.
 2. A lens according to claim 1, wherein said enlarged end portion of at least one loop comprises a knob.
 3. A lens according to claim 1, wherein: said collar is formed of harder material than the material of the at least one loop.
 4. A lens according to claim 1, wherein said loop is stretchable and is slidable relative to the collar during vision accommodation.
 5. A lens according to claim 1, wherein the collar has a slit along its length for opening for disposal of the collar about said loop.
 6. A lens according to claim 1, wherein said tubular collar has at least one flange for enhanced fixation in the capsular bag rim.
 7. A lens according to claim 1, wherein said collar has a serrated surface.
 8. A lens according to claim 1, wherein the collar has a frusto-conical lumen.
 9. A lens according to claim 1, wherein: the collar is disposed on the loop positioning the collar in a recess in a mold wherein the loop is molded through the collar.
 10. A lens according to claim 1, wherein: said loops and enlarged end portions are formed of one of (a) hydrogel, (b) acrylic, (c) an optic material, (d) silicone.
 11. A lens according to claim 10, wherein: the collar is disposed about the loop and the loop and knob material is expanded by hydration, whereby the collar is retained on the loop by an enlarged knob.
 12. An intraocular lens comprising: an optic having two haptics extending from the optic, at least one loop extending from each haptic, at least one of said loops having an enlarged end portion, and a substantially tubular collar disposed about said at least one loop and retained thereon by said enlarged end portion.
 13. A lens according to claim 12, wherein: said haptics are plate haptics extending oppositely from said optic.
 14. A lens according to claim 13, wherein: each haptic has at least one loop extending therefrom and having a tubular collar thereon.
 15. A lens according to claim 13, wherein: each haptic has loops extending oppositely from its outer end portion, and each said loop has a collar thereon retained by an enlarged end portion on each said loop.
 16. A lens according to claim 12, wherein said tubular collar is fabricated of harder material than the material of the loop.
 17. A lens according to claim 14, wherein said loops extend outwardly from edge portions of the haptics.
 18. A lens according to claim 12, wherein said at least one loop is flexible.
 19. A lens according to claim 14, wherein said loops are flexible.
 20. A lens according to claim 14, wherein said loops are stretchable and are slidable relative to respective collar during vision accommodation.
 21. A lens according to claim 1, wherein said collar has a slit along its length for opening for disposal about a loop.
 22. A lens according to claim 14, wherein said collars have slits along their lengths for opening for disposal about the loops.
 23. A lens according to claim 14, wherein the collars have respective flanges for enhanced fixation in the rim of a capsular bag.
 24. A lens according to claim 14, wherein the collar has a serrated surface.
 25. A lens according to claim 14, wherein the collars are disposed on respective loops by disposal thereof in a recess of a mold wherein loops are molded through the collars.
 26. A lens according to claim 1, wherein protrusions are defined on said loops in positions to retain the collars in proximity to the enlarged outer end portions of the loop.
 27. A lens according to claim 2, wherein protrusions are defined on said loops in positions to retain the collars in proximity to the knobs.
 28. A lens according to claim 4, wherein protrusions are defined on said loops in positions to retain the collars in proximity to the enlarged outer end portion of the loop. 